A copartnership



R. A. BROOKS. TIRE RETREADING APPARATUS.

APPLICATION FILED MAR. Ll, 192 0.

snzze Reis ued May 4, 1920.

INVENTOR. Mam

A TTORNEYS.

R. A. BROOKS.

TIRE RETREADING APPARATUS.

APPLICATION FILED MAR. H, 1920.

Bissued May 4, 1920.

. VEN TOR.

A TTORNEYS.

UNITED STA ES PATENT OFFICE.

ROSCOE A. BROOKS, OF CHICAGO, ILLINOIS, ASS-IGNOR TO WESTERN TIRE &RUBBER WORKS, OIECHICAGO, ILLINOIS, A COPARTNERSHIP.

TIRE-RETREADING APPARATUS.

Specification of Reissued Letters Patent. Re'issued luay 4, 1920Original No. 1,327,307, dated January 6, 1920, Serial No. 257,956, filedOctober 14,

1918. Application 'for reissue filed March 11, 1920. Serial No. 365,041.

To all whom it may concern:

Be it known that I, Rosoor: A. BROOKS, a citizen of the United States,residing at Chicago, county of Cook, State of Illinois, have invented acertain. new and useful Im provement in Tire-Retreading Apparatus, anddeclare the following to be a full, clear, and exact description of thesame, such as will enable others skilled in the art to which it pertainsto make and use the .same, reference being had to the accompanyingdrawings, which form a part of this specification.

My invention has for its obj ect to produce a simple apparatus forretreading tires, such as automobile tires, which shall not only operatemost efliciently but be easily manipulated so .as accurately to adjust atire to the same quickly and with a minimum expenditure of effort.

A further object of the present invention is to produce a simple andnovel tire retreading apparatus by means of which a uniform distributionof pressure may be obtained throughout any desired circumferentiallength without employing a multi-. plicity of clamping or pressuredevices. By avoiding-the use of a multiplicity of separately adjustableclamps or the like the great difficulty heretofore experienced 'insecuring a uniform distribution of pressure may be overcome andtherefore, viewed in one of its aspects, my invention may be said tohave for its object to produce an apparatus in which a uniformdistribution of pressure at the surface which is being retreaded will beinsured.

Another object of the present invention is to produce a tire retreadingapparatus means of which anti-skid designs of various kinds may beproduced in one and the same apparatus.

A. further object of the present invention is to produce a simple andnovel tire retreading apparatus which will permit antiskid designs to beworked into tires of various sizes in the same apparatus withoutdestroying the characterof the design at any point on account of thenecessity of making an overlap.

The various features of novelty whereby my invention is characterizedwill hereinafter be pointed out with particularity in the claims; but,for a full understanding of my invention and of its objects andadvanvention and adapted to retread a tire inthree sections;

Fig. 2 is a section on an enlarged scale taken approximately on line 22of Fig. 1, showing the clamp or pressure-producing device in its closedposition;

F 3 is a section taken approximately on line 33 of Fig. 1, on the samescale as Fig. 2, showing only the mold;

Fig. 4 is a section on line 44 of Fig. 1, showing only the tire and thepressure pro ducing means, the mold being omitted;

Fig. 5 is a-pla-n View of the two stationary matrix members shown in themold in Fig. 1. parts being broken away;

Fig. 6 is a section on line 6-6 of Fig. 5;

Fig. 7 is a top plan view of the movable be had to the followingmatrixmember arranged in the mold in Fig. 1-;

Fig-8 is a plan View of a section of a matrix adapted to form on thetread a different design from that produced by the use of the matrixshown in Fig. 5;

Fig.9 is a section taken on line 9-9 of Fig. 8;

Fig. 10 is a plan view of a fragment of a matrix showing a stilldifferent design;

Fig. 11 is an edge view of the matrix shownin Fig. 10; and

Fig. 12 is a plan View of a section of a matrix adapted to form a stillfurther type of design on the tread surface.

Reference being had to the drawings, 1 represents a hollow mold in theform of a trough-shaped segment. The circumferential length of the molddepends upon the number of sections in which the retreading of a tire isto take place. The apparatus shown is designed to retread a tire inthree sections and its circumferential length is therefore made slightlymore than 120 degrees. A circulation of a heating medium, such as steam,may be obtained through the mold, an inlet opening, 2. and an outletopening, 3, being provided for this purpose. here the inlet opening isat one end of the mold, a vent hole, 4, for the escape of air,-ispreferably placed at the opposite end,

so as to permit the outlet to be placed at the bottom without permittingair to be trapped in the mold. The trough, 5, of the mold is given theshape of the tire to be retreaded except that at the edges it flaresoutwardly as indicated at 6 so that there will be no sharp corner oredge left to make a mark in the tire. The ends of the mold arepreferably carried somewhat 'beyond the steam chamber 7 as indicated at8, and are gradually rounded off so that at itsextreme ends the troughof the mold becomes flaring and therefore prevents the sides of the tirefrom being marred at the ends of the mold.

The character of the tread surface is determined by a sectional matrix,10, fitted into the bottom of the trough. By making the matrix separablefrom the mold it can readily be removed and replaced for the purpose ofvarying the design. Where the design contains transverse lines orshoulders, as distinguished from mere continu ous ribs or depressionsextending circumferentially around the tire, it is necessary that meansbe provided to insure that there will not be an overlapping at themeeting ends of the first and the final retreaded sections. In the caseof any given tire a mold could of course be constructed which w -uldpermit the retreading to be done in sections which would exactly meet sothat there would be no overlapping; but, there is a considerablevariation in the circumferential length of tires of different makeswhich purport to be of the same size and, furthermore, it is quitefeasible, leaving out of consideration the design of the tread surface.t employ the same apparatus for retreading tires purporting to be ofdifferent sizes. Consequently it is necessary, in order not to restrictthe use of any individual apparatus, that some means should be providedto permit the mold to accommodate itself not only to different sizes oftires but to such tires having designs containing transverse linesorshoulders. To this end I make the matrix in sections, at least onesection being preferably fixed in the mold and at least one othersection being adjustable'so that it may be moved in the circumf erentialdirection and permit the lastsection of the tire to be retreaded withoutcausing an overlapping of the design between the adjacent ends of thatsection and the section that was the first to be retreaded. For the sakeof convenience in manufacture the stationary part of the matrix ispreferably madein two sections, 11 and 12; these members being placed inone end of the mold while the movable section, 13, is

simply laid loosely in the other end of the,

mold. The parts are preferably so constructed that air can pass aroundthe matrix underneatha tire placed in the mold and escape throughsuitable vent openings.

This may conveniently be accomplished by casting the matrices andleaving their under sides unfinished so that they will not have amachined fit in the mold and yet will fit with a sufficient de ree oftightness to hold them in place. he vent holes may conveniently beopenings or passages,- 14, extending through bosses or spacing devices,15, contained within the hollow wall or steam chamber of the mold; theseopenings 14 serving also to permit the insertion of bolts or thumbscrews, 16, which pass up from underneath the mold into the sec- I tion12 of the matrix. The bolts or thumb screws are made smaller in diameterthan the holes through which they pass and, in order to insure thatthere will be a free passage for the escape of air, the under side ofthe head of each of the bolts or thumb nuts may be grooved as indicatedat 17 in Fig. 3. The section 11 of the matrix may be held in place atits inner end by interlocking it with the adjacent end of the member 12as indicated at 18 in Figs. 5 and 6; while a thumb screw, 19, passesthrough the flange or wall, 8, of the mold into the outer end of themember 11 of the ber 13 is simply laid in place and, when the lastsection of the tread is to be worked upon, the member 13 is removed fromthe moldand laid on the tire with one end in registration with thedesign on the retreaded part; the matrix member being placed on the tirein such position that when the tire is located in the mold, the meetingends of the members 12 and 13 will not be spaced apart a distancegreater than one element of the design. Furthermore, the' design ispreferably so that by turning the member 13 end for end compensation maybe made which will give the operator the choice of either of twolocations. Thus, assuming that the tread surface is to have two rows ofsquare depressions and that the matrix will be made as shown in Figs.- 5and 6, that is, be pro- 20, the projections or matrix member may beplaced close to the edge while at the other end they may be placed atsome distance from the edge, as shown in Fi 7 Either the right hand endor the left hand end of the member shown in Fig. 7 may be placed againstthe right hand end of the member 12 in Fig. 5 or in the vicinity of thelatter end.

In Figs. 8 and 9 there is illustrated a matrix, 21, having circularholes or sockets, 22, for the purpose of producing a treadsurface havinground knobs.

In Figs. 10 and 11 the matrix, 23, has 1 0 disposed on the member 13 115vided with two rows of square projections,

at one end of the plate transverse broad, shallow ribs, 24, for thepurpose of producing a tread surface having cross bars.

The matrix shown in Fig. 12 has diamondshaped depressions, 26. In thesame way any other suitable 'or desired design may be formed on thematrix.

One of the difiicult problems is that of securing an even pressurebetween the tire and the mold, at all points along the mold. To this endit is customary to employ a sand bag in the form of a segment of aninner tire which is laid into the tire when the latter is placed in themold. In Figs. 1, 2 and 4 30 represents the tire upon which the work isbeing done and 31 represents the sand bag.

ent points along the sand bag for clamping the tire between the latterand the mold; this being a tedious process and one which does not insureuniform results. In accordance with the present invention there isemployed only a single clamping member which may conveniently take theform of a leaf spring, 32, made up of any desired number of superimposedleaves .of various lengths; the length of the longest leaf being asgreat as that of the mold. The spring is preferably given an initialcurvature which is less than that of the mold or the tire to be workedupon, that is, the spring is curved on a longer radius than the radiusof the tire. After the tire has been placed in the mold and the sandllii been located and pressure is applied to the center of the spring soas gradually to bend the spring i until it engages at all points throughits length with the sand bag and, through the latter, exerts adistributed pressure on the tire. As the ends of the spring are free itis possible, by properly proportioning the same, to secure a uniformequalized distribution of pressure throughout the whole sec tion of thetire which is being vulcanized. It is essential that no air pocketsshallform between the tire and the mold but, as the tire isprogressively forced into intimate contact with the mold from the outerends of the latter toward the middle, the air is forced inwardly anddownwardly and escapes around the matrix through the vent holes, 14,provided for that purpose, Consequently there can be no pocketing ofair.

Any suitable means may be provided for pressing the spring member. Inthe arrangement shown an arm, 33, is hinged at one end to one side ofthe mold at about the middle thereof, the arm being adapted to swingthrough atire in the mold to the opposite side of the mold; a dog orcatch, 34, being provided on the free end of the arm for engagementwitha ,fiange or shoulder, 35, on the mold. The arm may be provided witha socket, 36, into which a suitable operating handle, 37, may be placed.A heavy set screw, 38, is carried by the arm in position to overlie andengage with the middle of the spring 32. The device may be used in twoways. fter the set screw has once been adjusted for. a given tire, itsadjustment need not be changed as the tire is moved from one position toanother but all of the work may be performed by simply manipulating thehandle or lever, 37. On the other hand, if desired, all of theoperations except the mere locking and unlocking of the clamp, may beperformed by screwing or unscrewing'the heavy set screw.

The width of the spring will usually be considerably less than thediameter of the tire and therefore it may sometimes be found desirableto provide means for preventing the spring from slippin sidewise. Tothis end movable clips or ngers, 39, may be placed at the ends of thespring, they being so proportioned that when they occupy the positionshown in Fig. 1 they lie within the planes of the side edges ofthespring whereas, when they are turned on their pivots, 40, through anangle of 90 degrees to the position illustrated in Fig. 4, they engagewith the sides of the tire and center the spring.

The several plates of the spring may be held together by a rivet, 41,placed at the center and the lower or inner end of the set screw, 38,may be recessed as indicated at 42 so as to provide a seat for the headof the rivet and at the same time interlock the spring and the set screwso as tocenter the spring and prevent displacement in the lengthwisedirection or transversely in thefvicinity of the set screw.

While I have illustrated and described with particularity only a singlepreferred form of my invention, I do not desire to be limited to theexact structural details thus illustrated and described; but intend tocover all forms and arrangements which come within the terms employed inthe definitions of my invention constituting the appended claims.

I claim:

1. In an apparatus of the character described, a mold, a longitudinalspring member, and means for pressing said spring member into the mold.

2. In an apparatus of the character described, a mold curved from end toend, a longitudinal spring member having a lesser curvature than themold, and means for pressing said member into the mold until it conformsto the latter.

3. In an apparatus of the character described, a mold curved from end toend, a longitudinal spring member having a lesser curvature than themold, and means engaging with said spring member midway between the endsthereof for pressing said member into the mold until it conforms to Ithe curvature of the latter.

' rection of its length and adapted to receive a section of a tire, alongitudinal spring presser member having on the side toward the mold aface less sharply curved than the mold, and a power device engagin withthe said member at a point about midway between its ends to press thesame into a tire lying in the mold and increase the curvature of saidmember so as to exert on the tire a pressure distributed throughout thelength of said member.

6. In an apparatus of the character described, a trough-shaped moldcurved in the direction of its length along the arc of a circle, themold having vent openings at the middle to permit the escape of air fromunderneath the tire lying in the mold, and means for progressivelypressing a tire in the mold against the mold from the ends toward themiddle.

7. In an apparatus of the scribed, a mold, and a matrix extendingthroughout the length of the mold, said matrix being in sections one ofwhich is stationary and another, at one end of the mold is movable inthe direction of the length of the mold.

character de- 8. In an apparatus of the character described, a mold, anda matrix extendin throughout the length of the mold, said matrix beingin sections one of which is stationary and another, at one end of themold, is loose in the mold.

9. In an apparatus of the character described, a mold, and a matrixextending throughout the length of the mold, said matrix being insections one of which is movable in the direction ofjthe length of themold relatively to the remainder of the matrix, the matrix containing adesign for an anti-skid tread, and the design on the movable sectionbeing disposed differently with respect to one end of the latter thanwith respect to the other so as to permit a variation to be produced byreversing the movable member of the matrix.

10. In an apparatus of the character described, a mold, and a removablematrix seated in the mold, said matrix being in sections arrangedend toend, and'at least one of said sections being movable relatively to theremainder of the matrix in the lengthwise direction.

11. In an apparatus of the character described, a mold, and a matrixextending throughout the length of the mold, said.

matrix being in sections arranged end to end, and .at least one of saidsections being movable lengthwise in the mold independently of theremainder of the matrix.

12. In an apparatus of the character described, a mold, and a matrixextending throughout the length of the mold, said matrix being insections arranged end to end and movable in the mold relatively to eachother in the len thwise direction.

' ROCOE A. BROOKS.

